"Power Sweeping" is something you likely haven't seen yet and it is the most thorough way of cleaning chimneys of any size. 

For my first 2.5 years of cleaning I used old fashioned brushes and after completing all my WETT courses early 2017 and learning of new techniques in the industry I was a quick convert!! Loving this new technique! Its affects can best been seen here.

For harder jobs and an additional charge I can use a cable whip that doesn't damage and will completely clean the liner of any hard stuck residue. 

POWER SWEEPING IN ACTION!!